Plasma position control simulation with a simple model for new control coil system of KSTAR tokamak

Abstract

Summary form only given, as follows. Summary form only given. In-vessel coils are to be used for the fast plasma position control, field error correction (FEC), and resistive wall mode (RWM) feedback stabilization in the Korea Superconducting Tokamak Advanced Research (KSTAR) device. Recently, a new configuration that incorporates toroidal segmentation concept, has been adopted. The new coil system is found to allow a wider range of plasma control flexibility satisfying the KSTAR advanced physics requirements for the plasma position and FEC/RWM control capability, in addition to engineering advantages. With the modified coil structure, plasma position control has been simulated by using a simple linear /sup 1/RZIP (R, Z, I/sub p/) model. The RZIP model is developed as a simple circuit equation representing a linear plasma response model. This model can be easily constructed without solving plasma, equilibrium and is more explicit in the quantities that define the plasma response. By applying step response simulation and random perturbation simulation for the vertical position control, PID controller gain and power supply limit are compared with those of the previous axisymmetric internal control coils. Results from the simple model are benchmarked with the /sup 2/TSC simulation for axisymmetric internal control coils.